But it brings me to a similar question, since we are able to convert back and forth, carbs/fat/fat/carbs, it would seem like you would still be drawing from the total available. If you have your body in a run for 1 hour, you're body is going to have to find that fuel and use it. Hypothetically if it were 2-3 hours, that fuel would be burnt by physical requirements at the moment.

As far as I remember, HIIT's benefits for fat loss were that your body continues to burn at a higher rate for 10 hours or so after the workout. But not necessarily during the excersize? I'm mostly trying to figure out how to give these guys the most efficient workout I can. At the moment I don't think (this one) can crank out some good sprints without crashing and sliding along the ground.

I was thinking about the idea of "self selection." When I was young, 16-20 or so. I was just a lean kid. From that moment if I got into track and distance running, I would've developed into that build. Instead I boxed, and eventually developed the build of a fighter. If I were a sprinter, then I'd have that build. I agree though, that I never could've trained my way to be a 7 foot tall center, or a 250 pound sumo. But I could reasonably be a very lean runner, or at some other polar end of my genetic range.

If you don't trust my line of reasoning, ask yourself this: if we absorb whey the fastest, and we can only absorb about 10g of it per hour, and we're only ingesting it for 16 hours a day, that's only 160g of protein per day. Why would we need to worry about protein intake far in excess of this (see the section on "Maximal Rate of Urea Synthesis and Excretion")? If we can't absorb it, it never hits the bloodstream, and the worst it'll do is cause odd excretory patterns.

I was wondering about this too. From what I gather it's best to mix proteins through out the day. for instance, Whey proteins after you workout for fastest absorption when your body needs it right then, and then later in the evening, eat some lean red meat or chicken since it takes longer to absorb in your gut but presumably you'll get more out of it as it digests. Does that sound right? It seems to make since. Eggs and lean meats through out the day and whey or casein after exercise to give an immediate boost.

Here's another article I read on high fat low carb diets. I'm not convinced it would work for athletes since it sounds kind of Atkins-ish. Has anybody tried a high fat/low carb diet while maintaining a high protein intake (>1g protein / lb of body weight)?

But it brings me to a similar question, since we are able to convert back and forth, carbs/fat/fat/carbs, it would seem like you would still be drawing from the total available. If you have your body in a run for 1 hour, you're body is going to have to find that fuel and use it. Hypothetically if it were 2-3 hours, that fuel would be burnt by physical requirements at the moment.

I'm not entirely sure what you're asking. Would you mind rephrasing it for me?

Originally Posted by Nemesai

As far as I remember, HIIT's benefits for fat loss were that your body continues to burn at a higher rate for 10 hours or so after the workout. But not necessarily during the excersize?

I don't know if it's necessarily ten hours, but that's the theory. I'm still waiting for them to put people in a whole-room calorimeter and verify it experimentally, but there's a significant body of circumstantial evidence suggesting the theory's valid.

Originally Posted by Nemesai

I'm mostly trying to figure out how to give these guys the most efficient workout I can. At the moment I don't think (this one) can crank out some good sprints without crashing and sliding along the ground.

As I'd mentioned above, "sprint" in the context of interval training is more a measure of intensity than of motion type. Most of the studies I've seen so far involve doing "sprints" on stationary bikes, for instance. You could also do stairs, lengths in the pool, or any other activity where you break the aerobic threshold for a short period of time.

Does everybody understand that VO2max training and HIIT training don't necessarily have anything to do with each other?

By definition, high intensity usually refers to activities that take place under 45 seconds. This is because the body doesn't need oxygen to access energy in this time frame and has more naturally available. It's anaerobic.

After 45 seconds or so, the body reaches its anaerobic limit and needs oxygen (aerobic) to access its energy supply. Aerobic activity can go on for hours at a slower/less intense pace. That means that at 45 seconds, you can either slow down and recover or go aerobic.

VO2 max studies - because they measure oxygen use - are only concerned about aerobic activity, which is why all of the examples in the V02 link went on for at least 25 minutes total time. (15sec on/15 sec off for 25 minutes does not give you enough time to fully recover anaerobically so you end up using your aerobic capabilities).

HIIT training takes advantage of the fact that you can use up a lot of energy in a short amount of time (under 45 seconds) and generally alternates between anaerobic work and a recovery. Depending on how you do it, it can increase your VO2 max but that is only a side effect to fat burning.

For 45 seconds, your body won't require excess oxygen to access a fuel store? After 45 seconds, you either need to slow down or your body will put a demand for extra oxygen (faster heart rate/ breathing) to fullfill this need?

The more often you tax yourself physically for this 45 second period, the higher.. VO2Max you'll develope? The more intense, the better progress within that range?

But if you keep running after 45, you'll operate aerobically, to your potential, something limited by your VO2max? So basically do interval sprints to increase that value across the board and you'll be able to do long distance at a faster pace?

When you jog for 5 minutes, aerobic, and kick it up to a sprint for 30 seconds, then back to jogging. You're essentially stretching your VO2 limit, from a pace that is somewhere comfortably under, and returning back under that rate, to a jog.

I think I'm starting to understand that, if the above is close?

Now I'm trying to sort out the caloric demands, and how the interval training puts a tax on that compared to a 2 hour jog. Obviously I can appreciate getting a lot done in a 20 minute HIIT regiment, rather than be bored as hell on the trail for 2 hours. But if you are able to run for that length, at some point, does you're body require the stores you have to maintain that level of activity for that length of time? I'd always assumed it went for carbs first, then once depleted, fat, then muscle. Or perhaps some ratio shared across, like 90% from carbs 9 % from fat, 1% from muscle, while you still have carbs. Then like 95% fat 5%muscle after passing that stage of your energy store. This is all speculation. I can only base this on idea that I got a whole lot more cut when I started knocking out 3 trips of 7 miles a week. Something about being out for a long time with no food or water, forcing your body to eat what it needs, 'knowing' that there isnt other food at the moment.

Training was a lot easier when I had a trainer yelling at me what to do, now I've got the other shoes on and I'd like to be able to explain the why's of what we're doing rather than just saying, this is what we did before etc.

The 7 miler was always a full workout for me, 3-4 miles out and back, straight into the hot tub and rich food.

I did have to go out and run 5 miles round at the gym, then come back and spar 10 2-minute rounds. So it's possible I suspose. I just don't think I could've done it without having a choice in the matter, "Get in the ring white-boy" then getting swung on for the next half hour, you sorta just go to that happy place.

A three minute "sprint" is not HIIT; there's no way you're putting forth anything approaching high intensity for three minutes. Typical HIIT protocols have sprints that last between 10 and 30 seconds, with work/rest ratios anywhere from 2:1 to 1:4.

Heres my example
My typical jogging speed on a treadmill is 3.5mph. I will kick it up to 7.0mph for 3 minutes, drop back down to 3.5 for one minute. You don't need to start with 3 minutes, hence why I said for starters you can go 1:3. If I were to just do 1 minute could I amplify my speed to makeup for it? No I could not because I can't physically run 21 miles per hour. At some point you have to increase the duration.

Maybe outdoors you could amplify your efforts, but the higher impact is hard on some, and some workout in gyms.